1. Technical Field
This invention relates to air powered tools and is primarily concerned with an improvement in the arrangement for the mounting of handles on the housing of an air powered tool such as a grinder.
2. Background Information
The maneuverability of hand-held air powered tools such as grinders has popularized their use for a wide variety of production tasks for both large and small products. Some grinders are termed vertical grinders. A conventional vertical grinder includes a housing containing a pneumatically driven motor with a vertical power shaft serving as the spindle carrying a grinding wheel. One such grinder is shown in U.S. Pat. No. 3,749,530, wherein a pair of horizontal handles are attached to a cast housing. Pneumatic power is supplied to drive the air motor by way of a power air passage having one portion extending through one of the handles and a second portion cast into the housing. The portion of the passage through the housing connects with an intake opening to the motor at the top of the housing. More recently, grinders such as the one disclosed in U.S. Pat. No. 4,330,967 have been equipped with a guard completely surrounding the grinding wheel at the rear of the housing beneath the handles and having an open front area.
Under most service use conditions, the operator of a vertical grinder of the foregoing type positions the grinding wheel so that it is tilted slightly out of the surface plane of the workpiece with the forward peripheral edge of the wheel along the open front of the guard performing the majority of the work. The surface to be worked may be in any angular position from horizontal, to vertical to directly overhead of the operator.
Of importance to the versatility of the tool is that it provide a wide latitude and freedom of postures from which it can be easily operated. Moreover, it is of specific importance to the speed, quality and quantity of work performed using such grinders that the effort required of the operator in holding the grinder in any working position, even for extended periods of time, be kept to a minimum and that factors tending to fatigue an operator be eliminated if not reduced substantially wherever possible.